Automatically controlled burner apparatus for heating automobile engines



H. W. LlNDAHL AUTOMATICALLY CONTROLLED BURNER APPARATUS FOR HEATING AUTOMOBILE ENGINES 2 SHEETS-SHEET l Filed June 15, 1946 AUTOMATICALLY OONTROLLED BURNER APPARATUS ug- 5, i952 H w. LINDAHL `,0,

FOR HEATING AUTOMOBILE ENGINES Filed June l5, 1946 2 SHEETS- SHEET 2 Patented Aug. 5, 1952 AUTOMATICALLY CONTROLLED BURNER APPARATUS FOR HEATING AUTOMOBILE ENGINES Y Henning Waldemar Lindahl, Landskrona, Sweden I" ,Application Junev 13, 1946, SerialNo. 676,392 Y in Finland4 February i, 1941 section 1 Pub1ie Law 690, August s, 1,9456r Patent expires February 1, 1961 4 Claims.

A Y Y 1 v l For vehiclesfdriven by combustion engines 1t .hasV yalreadybeen proposed to keep the engine warm,v when the vehicle is not in use, by heating lmeanscoinprising a burner for liquid fuel, usually petroh as the source of heat. In such connection it has also already been. proposed to switch on the burner automatically by electrical means, when the engine has stopped running, and to switch ci the burner automatically by shutting oi the supply of fuel to the same, when the engine is again started. The meanshitherto proposed for. the purpose in viewfhave not become of any practical importance, however, because they were not so simple and reliable in function as is required.

The object of the present invention is tol remedy this disadvantage and to provide improved electrical means for automatically switching on and oi'l the burner which are simple andeicient in operation and particularly applicable in cases wherethe burner consists of a gasifying burner in whichl thev fuel is gasied by heat and is discharged under pressure in gasined condition through a nozzle into Va burner head 'invwhich the combustion takes place.

Eor'startingfeuch a gasifying burner pre-heating of the-pipe orrthe like in which the gasification occurs by means of a special source of heat is necessary, in thatthe, heating of this pipe or the likecanvbe carried out bythe burner itself only after` itjhas commenced tofunction. Y As such specialsource of heat it is well-known to use an .electrical heating element, 'andit is a further object of the invention to provide means for automatically switching on and off said element when required.

The invention will be described in more detail with reference to the accompanying drawings whichpartly.diagrammatically, illustrate an embodiment of the invention and in which:

'Figure 1 shows in section the assemblage of the apparatus according to the invention, y

Fig'u're`2.` to 5 diagrammatically show thermostatic means in various positions, and

AFigure 6 isacircuit diagram of the apparatus.

`Referring 'to Figure l in the drawings, I is an outer sheathk and l2 an inner corrugated wall which divides the interior of said sheath into an inner heating chamber 3 and a surrounding annular jacket 4. Theulatter is connected in the cooling water systemv of an internal combustion engine by means of an inlet connection pieceb atjthe bottom end ofthe sheath I and an outlet connectionpiece 6 at the upper" end thereof. y In ,the heating chamber 3, which is bounded at the 'theedge of the rst-mentioned part I8.

bottom by a perforated bottom wall 'I provided with a safety net 8 and at the top by a perforated cover 9 provided with a safety net I0, a burner Il is mounted which will be desc-ribed more in detail in the following and which communicates through channel means mounted in the bottom wall 'I with a fuel supplyconduit I2. This conduitfurther passes through an electromagneticall-y controlled valve device I3 which is mounted at the side of the sheath I or at any other suitable place. The control of the movements of the Valve takes place in response, on the one hand, to theA running or standstill condition of the engine and, on the other hand, to the temperature conditions in the heating chamber 3, which for this purpose encloses a thermostatic contact device I4 which is connected in the circuits 'of the valve as will be described with reference to Figures 2 to 5.

The burner II consists of a ball-shaped bnirner head I5 and a nozzlev I6, which latter is associated with the above-mentioned channel means which is in the form of a channel plug I'I, The whole burner is thereby supported by the bottom wall 'I of the heating chamber 3. rIhe burner head I5 is composed of. a lower cup-shaped part I 8 which has `a screw-threaded hole in its bottom with which it is screwed on tothe nozzle I6, `and of Yan upper reversed cup-shaped part i9 which vrests by means of a ledge around its periphery on The vupper ypart, IS is perforated or otherwise cut through at its top to provide an outlet for the combustion gases from the interior of the burner head l5. At the top of the part I9 a suppOrt in the form of a curved metal plate 20 is mounted by a central bolt 2l, said plate being provided with a great number of holes 22. In these holes the legs of hair-pin wires 23, preferably of fire.- proof steel alloy, are inserted, so that 'said wires are thereby suspended from the support`v 20 and hang down in the interior of the burner head I5. For igniting the burner a ilament 2,4 intended to be'heated electrically is provided within the burner head I5.

y The nozzle I6 projects a little ldistance upwardly into the burner head i5, and atits upper end a nozzlevendpiece 25 is screwed in which is provided with a ne passage. The lower end of the nozzle vhas an internally screw-threaded 'ange 25 with which it is screwed on to a corresponding Iiange' 2'! on the upper end ofthe channel plug I'I. The latter whichhas an axial channel or passage 2,8 for'the, fuel2 supply is further, in a peripheral groove. 29- in the part 32 which is screwed on to the latter outside the nut 3|. In the inner hollow 33 of the nozzle I6 a body 34 is movable which supports a cleaning needle 35 directed upwardly towards the nozzle end piece 25 and which normally rests on` a washer 36 loosely lying below thesame in va space 31 between the nozzle I6 and the channel plug I1. This washer is preferably circular, and it is so made from bimetal that at normal temperature it is curved in one direction but when exceeding a certain temperature reverses to become curved in the opposite direction to reverse again and become curved in the first direction when being cooled below said temperature. The reversal occurs so suddenly and with such a force that the washer jumps up from itssupport and throws the ybody 34 upwardly in the nozzle hollow 33, so that the cleaning needle 35 fastened on the body 34 is pushed up through the opening inthe nozzle end piece 25 and cleans the same. Due to its weight the body 34 immediately falls back again into its position of rest, so that said opening is shut off by the-cleaning needle 35 only for a short moment. At the ignition of the burner the heating of the nozzle I6 taking place thereby is suincient to reverse the bimetallic washer 36,from curvature in one direction to curvature in the other direction, and

accordingly cleaning of thenozzle will occur at every ignition of the burner. At the extinguishing of the burner and the ensuing cooling of the nozzle below the temperature at which the bi- .metallic washer 36 was reversed in the way indicated above the washeris again reversed, and

cleaning of the nozzle againtakes place. Thus the nozzle will be cleaned practically after every 4extinguishing of vthe burner and at the beginning of` every new ignition of the same.

@The thermostatic contact device I4 is placed adjacent-,the,burner II in the heating chamber 3,0"11`- a support 38 which consists of a cup-shaped element` clamped between the channel plug I1 and ltherbottom wall 1. -The contact device is thereby. subjected to the action of heat from the burner II as well as from the heating resistance 30. It consists, as is best seen in Figures 2 to 5, of a contact spring 39, preferably of Phosphor bronze, a bimetallic contact spring 4D having a biasing bow element, and a contact spring 4I, 'preferably of Phosphor bronze and provided with a biasing bow element, the bimetallic spring'40 lyingbetweenthe two other contact springs 39 and 4I cooperating therewith and being provided with an insulated hook 42 for oo -operation with the contact spring 4I The contact spring 39 is connected through a normally'closed switch 43 which is located within the casing of the valve I3, with one terminal of a Ycurrent source, usuallythe ordinary battery of the motor vehicle. ,To the other terminalof the current source the bimetallic contact spring 40 is connected through the heating coil 30 and the lfilament V24, and to the last mentioned terminal ofthe current source the contact spring 4I is connected through a magnet coil 44 in the valve device I3.4

,'Ijhe valve device. I3 comprises a bracket 45 and a casing 45 mounted thereon, said casingenclosing the above-mentioned coil 44 as well as another coil 41 situated below the former and connected to the electrical generator of the motor vehicle or in any otherway soas to be energized as soon as the engine starts.'` The two coils surround a tube 4B which extends vertically through the interior of the casing 46 and which is connected at its bottom to a channel plug 49 in the bracket 45 and projects at its top'through the casing. The outer end of the channel plug 49,"which has an axial channel 50, is connected by-means of a cap nut 5I with the fuel supply conduit I2, and the upper end of the tube48 is provided with a connection piece 52 for another conduit (not shown) coming direct from the fuel supply. Within the tube 48 a rod core 53 is provided freely movable. The lower end of the core, which is guided in a bushing 54 within the tube, is formed as a valve needle which is intended to shut off the channel 50 whenjthe c ore occupies its lowest position, and the upper end of the core is formed with a thickened portion 55 which is intended to be engaged by a-.spring clamp -56 at the'upper end of theA tube 48when the core is raised into its uppermost` position. Intermediate its end the core V53 is provided Awith a cylindrical .soft iron piece 51y which is situated so as to be attracted by either coil .44 or 41. The above mentioned switch 43 consists of a contact spring which is fixed .to .the vbracket 45 and with a contact member 58 normally engages the head of a clamping screw 59 to which a lead to the current'source is connected. The contact spring 43 is connected by a lead with the heating coil 30 of the burner II and carries an armature 6I) which surrounds the .tube"48. andcan be attracted by thelower coil 41, whereby it is raised into a recess, suited therefor in said coil.

vThe complete circuit of the apparatusas described above isshown in Figure 6.

The operation of the apparatus Vis as follows. As. soon as the engine is started the coil 41V is energized and draws the core 53 downwardly ,and the armature 6U upwardly, the valve being closed, Vthe fuel supply to the burner I I shut 'off 'and the batteryy current to the contact springy 39 interrupted by the switch 43. The burner I I is maintainediully out of action as long as the engine is running When. the engine is stopped. the current through thecoil 41 ceases, and then the switch 43 connects the contact spring 39 to the battery. As soon. as the temperature in the neighborhood of the bimetallic contact device I4 has sunk below a predetermined point,.the bimetallic contact spring 40 engages the contact spring 39, as shown in Figure 2, whereby the heating coil 3D and the filament 24 are connected in circuit. When the pre-heating produced by the heating coil is suicient, the bimetallic contact spring 40,v while maintaining its engagement with the contact spring 39, engages the contact spring 4I, asY shown in Figure 3. .Thereby the coil 44 in the fvalve device I3 is connectedin-circuit; it lifts the core. 53 and opens the valve, -so that fuel is admitted through the conduit I2 yto the burner nozzle I3 where it is gasifled by the heat from the coil 30, the nozzle I6 and the heating coil 3D comprising fuel gasifying means. The burner Il risthen brought intooperation, in that thegasined fuel discharged through the nozzle wia-ignited within the burner head I5 bythe filament 24 provided therein. Y Aftervth'e 'burner has thus vbeen brought into operation the temperature inv the neighborhoodof the bimetallic contact device wljincrea es;k and when the bimetallic vcontact spring lili asa consequence bends further, it passes' the unstableposition of equilibrium of its bow element, so th'atrthis bow element which hitliier-"to,A by' its inherent tension, has tended to bend the contact spring 4l) towards the contact spring 39 reverses thefdirection of its action and suddenlybend-s freeyof the contact spring V3S andsimultaneouslybends they contact spring'AI-Wh-ich thereby, alsopasses the unstable position ofequilibriuniof.its-bow element.-` vThe position now -1occupied,l .;v,;ithe contact device is shown in Figure "At the cessation of the contact between the contactsprings 3,9 and 'All the' heating' coil V3i), Vthe filament Z4' and the" magnet oi'llili"are"disconnected- "At the disconnection of the latter the core 53 remains in its valveopening position, until the magnet coil 41 is again energized, by the spring clamp 56 holding the thickened portion 55 of the core. The bimetallic spring 40 naturally remains out of engagement with the contact spring 39, as long as the burner is in operation or the temperature in the neighborhood of the contact device otherwise remains at a suiiicient height. When the engine has been running and the burner as a consequence thereof has been out of action, lthe temperature will fall after stopping the engine. The birnetallic spring 40 then, in passing the unstable position of equilibrium of its bow element, bends in the opposite direction towards the contact spring 39 and by the hook 42 returns also the contact spring 4i through the position of equilibrium of its bow element, as will be seen in Figure 5, so that the position shown in Figure 2 is again reached.

I claim:

1. An apparatus of the type described, cornprising means forming a heating chamber, burner means mounted within said chamber, fuel gasifying means provided in said burner means including electrical heating means, a conduit adapted to lead from a fuel supply and connected to said gasifying means, electromagnetic valve means connected in said conduit and comprising reciprocable core means, a valve closing element on said core means, two axially disposed magnetic coils surrounding said core means for alternately actuating the same in the valve opening and closing directions, respectively, one said coil being adapted to be connected in the generator circuit of an automobile engine to which the apparatus is applied and upon energization thereof moving said core to valve closingy position, said coil being energized only during operation of said` engine, and thermostatic means for switching on andr oif said electrical heating means and for controlling the energization of the valve opening coil in response to the temperature in the neighborhood of said burner means, said opening coil of said electromagnetic valve means being energized by said thermostatic means to move said valve means in a conduit opening direction when the heat in said chamber reaches a predetermined temperature, said heating means being energizedby said thermostatic means when heat in said chamber reaches a ytemperature below a predetermined temperature.

2. An apparatus of the type described, comprising means forming a heating chamber, burner means mounted within said chamber, fuel gasifying means including electrical heating means provided in said burner means, a conduit adapted to lead from a fuel supply and connected to said gasifying means, valve means connected in said conduit, electrical switch means con- 6, nected-in 'the circuit of said ,electrical .heating means, `v electromagnetic means comprising. two axially disposed magnetic coils and Aa Vmovable core .foroperating rsaid valvemans and fsaid switchfmeans, rone said coil being' adaptedto be connected in thegenerator circuit .ofanautomobile vtol which the apparatusis` appliedfand upon energizationrthereof moving Vsaid .core to valve closing position andv said .switching means tdcircuit opening.' position,=and .ithermostatic meansfor Aswitching on' and off said telectrical heating means and for controlling thelenergizationof the valveopening coil Vof said valve means in responseV tolthe' temperature in the neighborhood. off said burner means',` saidv opening 'coilof said electromagnetic'valve means ybeing energized by said `therniostatic' meanslto' move said valve means in a conduit opening direction when the heat in said chamber reaches a predetermined temperature, said heating means being energized by said thermostatic means when heat in said chamber reaches a temperature below a predetermined temperature.

3. An apparatus of the type described, comf prising means Aforming a heating chamber,

burner means mounted within said chamber, fuel gasifying means including electrical heating means provided in said burner means, a conduit adapted to lead from a fuel supply and connected to said gasifying means, electromagnetic valve means connected in said conduit and comprising reciprocable core means, a valve closing .element on said core means for coacting with said conduit, two axially disposed magnetic coils surrounding said core means for alternately actuating the same in the valve opening and closing directions, respectively, one said coil being adapted to be connected in the generator circuit of an automobile to which the apparatus is applied and upon energization thereof moving said core to valve closing position, electrical switch means having an armature thereon and operatively associated with the valve closing coil of said electromagnetic valve means and connected in the circuit of said electrical heating means, said switch means being opened on energization of said one said coil by action of said armature, and thermostatic means for switching on and oi said electrical heating means and for controlling the energization of the valve opening coil in response to the temperature in the neighborhood of said burner means, said opening coil of said electromagnetic valve means being energized by said thermostatic means to move said valve means in a conduit opening direction when the heat in said chamber reaches a predetermined temperature, said heating meansbeing energized by said thermostatic means when heat in said chamber. reaches a temperature below a predetermined temperature.

4. An apparatus of the type described, comprising means forming a heating chamber, burner means mounted within said chamber, fuel gasifying means including electrical heating means provided in said burner means, a conduit adapted to lead from a fuel supply and connected to said gasifying means, electromagnetic valve means connected in said conduit and having a closing coil adapted to be connected in an automobile generator circuit and operable to closed position upon energization of said genera-tor, electrical switch means operatively associated with said electromagnetic valve means and connected in the circuit of said electrical heating means for opening said circuit when said valve closes, Vand `thermostatic 'means in said heating chamber connected in circuit with Said electrical heating means and with a valve opening coil of said valve means to controlathe operation thereof in response to the temperature inthe neighborhood of said burner means, said opening coil of said electromagnetic valve means being `energized by said thermostatic means to move said Valve means. in aconduit opening direction when the heat in saidV chamber reaches a predetermined temperature, 'said heating means being energized by :said thermostatic means when heat, in saidv chamber reaches a temperature below a predetermined temperature, said electrical switch means and said thermostatic means being connected in series.

I HENNING WALDEMAR LINDAHL.`

REFERENCES CITEDr 'I The following references are of record in the le of thispatent:

UNITED STATES PATENTS Number Number Y Name Date Danuser et al. Mar. 16, 1937 Hammers et al.; Mar. 8, 1938 Spencer 'QMay 10, 1938 Danuseret a1. f.' May 23, 1939 Holthouse ..'"June 16, 1942 FOREIGN PATENTS,

Country Date Canada July 28, 1942 Great Britain June 19, 1947 

